Underreamer.



A. G. HBGGEM.

UNDERRBAMEB..

APPLIUATION FILED JAN.26,1909

Patented Jan. 17, 1911.

Cil

ALFRED G. HEGGELVI, 0F COR-AOLIS, ENNSYLV'ANIA, ASSIGNGR TO OIL VJELLSUPPLY COMPANY, GF ITTSBURG, PENNSYLVAN CRPOBATION OF PENNSYLVANIA.

UNDEREAMER.

Specification of Letters Patent.

Patented Jan. i7, i911.

To all whom it may concern:

lle it known that l, ALFRED G. Hneenn, a citizen ot the United States,residing Coraopolis, in the county of Alleghenyv and ite oi`Pennsjilvania, have invented cert:v `n uen.v and useful improvements inUnderreainers; and l do hereby declare the Jrolloiving to be a full,clear, and exact description et the inventionl` such as Will enableothers skilled in the artto Which it appertaius to make and use thesame.

My invention relates to the construction of that class ot' devices knownas underreaniers, which are employed for enlarging the bore ot rtesianand like drilled W lls ivhere casing is used and the tool is introducedand withdrawn through the casing. ln this class of devices, the reamingbits should not only be so connected to the stock or mandrel as to beexpansible and collapsible, but the connections should be such as willpermit the ready removal ot the bits .tor sharpening` when required. Thebits and -their supports on the mandrel or stock should also be et' acharacter which Will insure the integrity oit the bits and theirconnections When subjected to the severe shocks and strains of service7While the tool as a whole should be et such a character that it willreadily tree itself from sand and silt xvh en it is desired to Withdrawsaid tool from the Well. The preferred torni oit this class ot' tools isone wherein the bit-stock or inandrel is provided with bit-slots havingin their lateral Walls Ways for retaining` and guiding the bits,abutments to support the bits against shocks when in service, and adistance block to maintain the bits in an cxpanded or operativeposition. To such a mandrel or stock the bits are slidingly connectedand are actuated by a spring` through the medium otl a cross-key or barthe ends ot which enter slots in the tangs oit the bits.

In service several points of Weakness have developed in the presentconstructions ot iniderreainers, leading, at times, to the loss of thebits in the Well and expensive iishing operations to remove said bitsand thus reclaim the Well. Among the most important or' these detectsare: Weakness of the stock adjacent to the bit receiving guide-Waysformed therein; Weakness of the bit-Shanks due to slotting the same forthe reception ot a cross-key connecting the bits With the actuatingspring; and detects in the form of distance block and bits Which preventhe cavity of the stock from readily freeing itseltl from sand and siltwhen the tool is vvithdraufn from the Well. rlfhis latter defeet oftencauses the tool to stick and neces lsitates the use et' drill jarsWhich, on account ot the packing ot the sand, are apt to detorin orshear ott the key or break the bitshank, and cause the loss of one ormore of the bits in the Well.

To overcome these several defects in underreaniers is the object, of mypresent invention.

To effect the reinforcement of the stock at the points Where the lateralstrains from the bit are resisted, i bevel the outer Walls of the bitWays, so that said outer Walls shall form an obtuse angle, whereby anincrease in the body of metal of the stock is effected and the depth ofthe Ways may be reduced; and such a construction embodies one teature ofmy invention.

To eitect the reinforcement of the bitshanks l dispense with slot andkey connections between the bits and the actuating` and in lien thereofemploy solid bit JIJL shank with an inwardly projecting over-hang whichis adapted to engage a bit-block that is interposed between the bits andthe actnating spring, whereby not only is the body of metal in thebit-shank increased at the point most liable to suffer fracture, but thebearing` and support of the bit on the abutment of the stock is alsogreatly increased: and such a construction embodies a second teature otmy invention.

To etfect the ready clearance or discharge ci sand, etc., from thecavity ot' the stock vvnien ivithdravv'ing the tool from the Well, thetop ot the distance-block is inclined and thc lateral Walls thereof aretapered doivnivardly, whereby jarring operates to displace laterally anysand which may have acciunulated in the stock cavity and to permit itseasy escape through the spaces between the bits and the side Walls ofthe distance block, said spaces, on account of the tapering form of thesaid distance block, attording increased opportunity tor the egress otthe sand as the bits slide downwardly: and

such a construction embodies a third teature ot my invention.

There are other, minor, features of inven- Cil longitudinal centralsection of the bit-stock,

showing the bits in side elevation, in an ei;- panded or operativeposition. Fig. 2 is a similar view ot the lower end ot the bitstoclr,the reainer-bits being in the position they occupy when being introducedin or withdrawn trein the casing; Fig. 3 is a longitudinal centralsection ot the lower end ot the bit-stoel; 'taken in a plane at rightangles to Fig. 2; Fig'. l is a transverse section ot the bits and bitstock or mandrel, talen in the plane ot the line t-f.. l; Fig. is a.transverse section of the device, taken in the plane et the line Fig. l;Fig. 6 is a detail perspective view or the bit-block; and ljig. 7 is adetail perspective View of the upper end oit the bit-shank, showing theoverhang` thereoiQ which engages the bitblock.

Like symbols refer to like parts wherever they occur.

l will new proceed to describe my invention incre fully so that othersskilled in the art to which it appertains niay apply the same.

ln the drawings, A indicates the bitstoclr, B the reainingr bits whichare slidiiigly arranged in the bit slots a of the stock7 C a tensionspring for actuating the bits,

@sacas ways, which taper or decrease in width from below upward, areformed with the beveled walls 5f or so that the outer walls oit the waysi'orin an obtuse angle, such a construction resulting in an increasedcross-section of metal in the stoel; at the points where the lateralstrain et the bits is to be resisted.

and also enablingthe depth ot' said ways or and D a bit-block torconnecting'` the bits 1- with 'the bit-actuating` spring C.

The bit-stoel; or niandrel this provided with a central bore l Jlor thereception of the bit actuating' spring' C, the lower portion of saidbore being' of sufficient dialneter to accoinniodate the spring', but.the upper portion thereo't being preferably formed vith decreaseddiameter, as at la, to thus forni a shoulder l" tor the support ot abolt by which the bit actuating` tension spring is anchored to thebit-stock.

The stock er at its lower end is transversely and vertically slotted totorni the lateral slots o for the reception ot the rangs ot the bit andto also torni the distance blocl 2 :tor expanding; the bits andinsintaining' than in operative position. This slotting of the steel;also results in forming' thereon upon or inner abutinents 3 whichadjacent to their cutting edges.

llorincd in the lateral walls of the bitslots o1" the stock are ways 5tor the guidance and lateral support of the bits.

recesses to be decreased.

ln order to cause the lateral displacement et any tine sand or likeinatter which inay accumulate in the cavity ot the stock, the topsurface or" the distance bloclr 2J is sloped or inclined5 as at Q; andin order to provide 'for the discharge ot the displaced sand thelateral. surfaces ot said distance bloei; are tapered downwardly andinwardly, as at 2b, so that as the bits descend to the collapsedposition, as shown in `i`g'. 9, a clearance channel will be torinedbetween the shanlrs ot the bits and the lateral surfaces et the distanceblock. The lower surface ot the distance block may be flat it desired.

The bits B have the usual lateral. shoulders or alnitnients (i whichengage the abutnients fl on the lower cud ot' the stoel; fr, and areprovided with lateral ribs i on the tanigs 7 which enter the ways 5 inthe lateral walls oit the bit slot u olf the stock. 'llhe ribs 7 arebeveled to correspond with the bevel l f1 on the y'all of the way 5, orguide rec The interior taces ot the shanlrs o'l the bits are cut bach orrecessed. as at 8. to accountmdate the interi ediate distance block Qwhen the bits are drawn down and collapsed7 as indicated in Fig'. 2 etthe drawijiulj, and tl c upper ends ot the bits project. inward to tornishoulders or overhannjs 9 which7 when the bits are in position in thestocln extend over and engage thc bitv bloclr D. Upon the upper andinner end ot cach bit-shank is a projection or nipple 5l whichcorresponds with the diameter ot the spring' receiving); bore ot thestock. These nipples are adapted and intended to enter said bore l andassist in supporting the bit against lateral strain and displacement:when in operation. rlhis ccnstriuztion of the bits not only leaves thebit tanpjs solid and therefore better adapted ed to res .et strains orcrushing: torce, but also materially increases the bearingv area ot theupper ends oit the bits on the zii/utinents oit the stoclr. rthe und.rtaces said overhanegs 9 are preferably hollowed out slightly, but maybe perfectly plain or tlat it desired, while their inner 'races arevertically recessed or slotted. as at El t' 01" the reception ot thestern l0 oit the bit bloclr l).

D slightly less width tran the width oit the bit-slot c in which itinoves. the arca ot the under surface ol the bit-block beingapproxiinately that ot the cross section ot that por- These l tion etthe slot in the stoel; intermediate ol indicaties the bit-block which isot j lOO the rcainer bits. rlhe bit-block is provided with a fiat barstem l() having at its upper end an elongated eye or slot 10 for thereception of a hook on the lower end of tension spring C. intermediateof the block D and eye 10, preferably at the bottom of the eye, thestem. 10 is provided with an enlargement or collar 11, the function ofwhich is to cause the bits B to Ydescend uniformly in case one bitshould stick or for any reason tend to lag: behind the other.

The spring; C, by means of which the bits B, are held in place on theabutments 3 and 4f when the underreainer is in operation, provided atits lower end with suitable means, such as a hook c, for engaging thebitsbloclr D, and said spring is preferably anchored at its opposite endon the stock by means of an internally threaded plug or nut 121, and athreaded bolt 12, the head 12" of which engages the shoulder 1b in theupper end of the bore of the stock A.

1n assembling' the elements of the underreanier the hoolr c on the lowerend of the tension spring C is entered in the eye 10a of the bit blockD, and the spring is inserted in the bore 1 of the stock A. The springis then anchored at its upper end to the stoel; by means of the bolt 1Qand plug` The spring` C having' been thus anchored on the stock thebit-block D is drawn down until the eye 101 emerges from the bore 1 ofthe stock into'the bit-slot a. thereof and a rod is passed through saideye below the hook c to hold the springextended. The bits B, B are nextinserted in the bit-slots a, u from below, so that the ribs T on the bitshanks shall enter and pass up iu the ways 5. When the upper ends of thebit Shanks have reached the lower face of the bit-block D. the upperends of the bit-Shanks zi are tilted outwardly, which the lateral playof the ribs 7 in the ways 5 permits, until the over-hangs E) pass thebit-block D, after which the bits may be tilted inwardly until. theover-hangs 9 thereof extend over and engage the said bit-block.Thereafter, upon withdrawing the rod which has been passed through theeye 10a of the bit block stem 10 to retain the spring' C extended, thereaction of the spring` will draw the bits D, B upward until the upperends of the tangs t rest solidly on the abutments of the stock and tl eshoulders 6 engage the abut-ments 4l: on the lower end of stock A. Inthis movement of the bits the nipples or projections .9 on the upperends of the tangs` enter the bore 1 of the stock, in which posit-ionthey afford support for the bits during the operation of the tool, andalso resist the inward movement of the bits resulting from wear of thecutting` edges thereof.

`When it is desired to introduce the tool into the casing the bits aredrawn down into the position shown in Fig. 2 of the drawing,

when the underreainer will pass into and through the casing.

lf it is desired to remove a bit for sharpeninp or for any otherpurpose, the bits are first drawn down to the position shown in Fig'. Qand rod is then passed through the eye 10a of the bit-block D to holdthe latter down and the springI C extended, after which either or bothof the bits may be readily removed from the stock fr by reversing' theseveral movements of the bits noted in the foregoingl description of themanner of assemblingthe elements of the underreaincr.

ln withdrawing,T the underreamer from the well, the tool is lifted untilthe engagement of the outer surfaces of the bits with the lower end ofthe casing arrests the upward movement of said bits, while the `upwardmovement of the stock A continues. This causes the spring C to be put intension, which permits the distance block D to ascend until it oppositethe recesses S in the inner faces of the shanlrs, whereupon the bits D,B collapse and assume the position shown in Fig. This permits the bitsto enter and pass through the casing.

Having thus described my invention, what I claim and desire to secure byLetter' latent is:

1. In an underreamer, the combination of a mandrel or stock having`bit-slots the lateral walls of which are provided with ways the outerwalls o-f said ways meeting at an obtuse angle, and sliding reamer bitseach provided with laterally projecting` ribs said ribs having a crosssection conforming to that of the ways in the walls of the bitstock.

2. 1n an underreainer, the combination of a mandrel or stock which isslotted trans versely to form communicating bit slots having theirlateral walls provided with ways, reamer bits movable on the stock, eachof said bits having laterally projectingribs movable in the ways of itsbit slot and having a solid tang formed with an inwardly projectingoverhang whereby it is supported by a bit block, a bit block slidable inthe slot of the mandrel intermediate of the reanier bits, the area ofthe under surface of said bit block l eing` approximately that of thecross-section of that portion of the slot which. is intermediate of thereamer bits, and means on the bit stock for maintaining the reainer bitsin expanded position.

3. In an underreamer, the combination of a mandrel or stock having abit-slot, reamer bits and a bit-block slidable in the said bitslot, thereamer-bits having overhangs which engage the bit-block, and thebit-block having a stem provided with a collar which projects over theoverhangs of the reamer-bits.

4. In an underreamer, the combination of a mandrel or stock which isslotted transversely to form communicating bit slots having theirlateral walls provided with ways, a distance block at the lower end ofthe mandrel for maintaining the reamer bits in expanded position, saiddistance block having its upper surface inclined, reamer bits movable onthe stock, each of said bits having laterally projecting ribs movable inthe ways of its bit slot and having a solid tang formed with an inwardlyprojecting overhang whereby it is supported by a bit block, and a bitblock slidable in the slot of the mandrel intermediate of the reamerbits, the area of the under surface of said bit block beingapproximately that of the cross section of that portion ot' the slotintermediate of the reamer bits.

5. In an underreamer, the combination of a mandrel or stock which isslotted transversely to form communicating bit-slots having theirlateral walls provided with ways, a distance block at the lower end ofthe mandrel for maintaining the reamer bits in expanded position, saiddistance block having its upper surface inclined and lateral surfaceswhich converge from above downward, reamer-bits movable on the stockeach of said bits having laterally projecting ribs movable in the waysof its bit slot and having a solid tang formed with an inwardlyprojecting overhang whereby it is supported by a bit block, and a bitblock slidable in the slot of the mandrel intermediate of thereamer-bits, th-e area of the under surface of said bit-block beingapproximately that of the cross section oi that portion oit' t-.he sloty which is intermediate of the reamer bits.

6. ln an underreamer, the combination of a mandrel or bit stock havinga. bore, bitslots and lateral abutments formed by said bit-slots, adistance block at the lower end of the mandrel for maintaining thereamei'- bits in operative position, 4a bit-block or bit support movablein the slot of the mandrel above said distance block, and i'eamer-bitssupported by said bit-block and having on their upper surfaces whichengage the abutments projections which enter the boi'e ot' the stockbetween said abutments.

7. In an underreainer, the combination of a mandrel or stock having abore, bit-slots and abutments adjacent to the bore and in planes atright angles thereto, a distance block at the lower end of the mandrelwhich maintains the reainer-bits in operative position, a bit-block orbit-support having a stem and which is movable in the slot or' themandrel above the distance block, and reamer-bits each having` on itsupper end an inwardly projecting overhang which engages an abutment onthe stoel; and which takes over the bit-block and is supported thereby,said overhang` having a projection which enters the bore of the stoclr.

8. A mandrel or stock for underreamers said mandrel having a slot whichextends transversely therethrough forming communicating bit slots, thelateral walls of the bit slots provided with ways the outer walls ofwhich form an obtuse angle, said ways adapted to receive ribs ofcorresponding cross-section on reamer bits which are adapted to co-actwith the stock.

In testimony whereof l aiiix my signature, in presence of twosubscribing witnesses.

ALFRED G. HEGGEV.

Vitnesses Louis C. SANDS, W. W. ANDERSON.

